a. Field of the Invention
This invention relates to an optical system for microscope tubes.
b. Description of the Prior Art
A microscope so formed that the inclination angle of an observing tube may be variable is already known, for example, from U.S. Pat. No. 4,299,439 and others. In such known system, as optical elements are arranged in a plane cutting the microscope by extending forward and rearward so as to vary the inclination angle of the tube, the separating distance between the position of the eye point of the eyepiece and the optical axis of the objective will be so large that there has been a problem in the operation that, in the case of operating the focusing handle, the hand must be extended greatly.